For low vision specialists and those who consult them
Don’t forget refraction!
July 13, 2010Posted by on
There is a nice paper in the most recent issue of Ophthalmology by Janet Sunness and Jaafar El Annan which reminds us of the importance of performing a refraction (spectacle test) for our patients with low vision. This should not be newsworthy to people who perform low vision evaluation routinely, but should emphasise the importance of refraction to our colleagues who do not see many patients with visual impairment.
In the paper, Sunness examines the records of 739 low vision patients newly referred to her clinic. In 11% of them, visual acuity was significantly improved (by more than 2 lines on a logMAR chart) by prescribing them new spectacles.
The authors make the point that people with eye disease often inappropriately assume that ‘new glasses’ will solve all of their visual problems, which is very rarely the case. However, that doesn’t mean that a spectacle test should not be performed for people with low vision: for these 81 patients in Sunness’ practice, visual function is likely to be better (although not perfect) after new glasses are prescribed.
The paper also makes the excellent point that retinoscopy and keratometry can be useful adjuncts to refraction in people with low vision. For this reason, I think it is important that an optometrist (or an ophthalmologist who performs refraction) is an integral part of the low vision multidisciplinary team.
In summary: low vision practitioners should not forget to perform a refraction for all of their clients with low vision. And whilst people with severe eye disease should not expect glasses to solve all of their visual problems, they may find they perform slightly better with an updated spectacle prescription.